I have a steel pole barn at my compound
IT'S THE ONLY WAY TO GO
No painting, no caulking, no BS every 5 years.
Go steel, only way to go.

Sorry, was done one year before I bought the place, but I could find out who did it if you really want to know

BTW, steel is coming down, it's way off it's highs.
better now than this last summer.

Make sure you do a concrete floor (big bucks!!!!) and get it insulated, even if you don't heat it initially.